This application claims the priority of German application number 197 44 715.5, filed Oct. 10, 1997, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a lighting device for the rear end of a vehicle, having at least one light chamber in which at least one incandescent lamp is disposed. A main reflector which emits light substantially rearward is associated with the incandescent lamp. A transparent cover is used to cover the light chamber. The light chamber also has a side light system disposed therein, along with a secondary reflector. Here, the secondary reflector is arranged in the light chamber such that light rays striking it are directed outward at least approximately transversely of the direction of travel of the vehicle.
U.S. Pat. No. 4,831,503 discloses a lighting device of this kind for the rear end of a vehicle, especially a motor vehicle. In a lighting compartment with a transparent cover, in addition to the incandescent bulbs with their rearwardly directed main reflectors, a side light arrangement is provided. This side light system has an incandescent bulb and a secondary reflector which deflects a portion of the light beams from the bulbs transversely across the direction of travel of the vehicle.
German patent document DE 40 21 987 C2 discloses another lighting device which is claimed to have small vertical dimensions and an optimum distribution of light.
In German patent document DE 42 24 061 C2, a vehicle rear light, especially for bicycles, is described. Here, a light-emitting diode is provided as the light source. Since light-emitting diodes naturally possess only a narrow light dispersion angle, the reference claims to achieve a larger, rearwardly directed luminous surface by using a light-scattering belt or a reflector.
In U.S. Pat. No. 5,567,036 a boundary and marker light, especially for truck roof lights, is described. A plurality of light-emitting diodes aimed in different directions serve as the light source. Together with the configuration of the transparent cover over the light-emitting diodes, emittance of light in a dispersion angle of up to 180.degree. is ensured.
German patent document DE 195 47 861 A1 describes a possibility for keeping the space occupied by a lighting device as low as possible. To achieve this, a special light-conducting body is used, which is disposed between any light source and a transparent covering of the lighting device.
German patent document DE 296 02 186 U1 discloses a universal vehicle lighting device, wherein reflector strips and light-emitting diodes, among other things, are provided. However, no information on the configuration and design of this lighting device is included in this disclosure.
It is therefore an object of the present invention to obtain a rearwardly directed illumination and excellent lateral lighting for the tail light of a vehicle, while at the same time keeping the space it occupies and the manufacturing cost as low as possible. Lateral lighting in the form of a side marker light or a side light arrangement is prescribed by law in the U.S.A., for example, and therefore this requirement is to be satisfied by the present invention without great technical cost.
This and other objects and advantages are achieved by the lighting device according to the invention, in which along with the known incandescent lamps whose light output is directed substantially rearward, a side light arrangement is provided with light-emitting diodes that are aimed at least approximately forward. This has the effect of creating lateral lighting. A sufficient lighting effect is achieved due to cooperation with a side reflector by which impinging light rays, which run roughly in the direction of travel, are conducted outwardly at least approximately transversely to the vehicle's direction.
If in this case the direction of emission is directed slightly forward, for example, by about 10 degrees, the side marking light required by law in the U.S.A. is easily obtained.
In a preferred manner, the lighting device according to the invention is used for the vehicle's tail light operation. Of course, however, it can also be used in the same manner for the brake lights and the turning indicators.
In an advantageous embodiment of the invention, a very good and uniform lateral emission of the light produced by the light-emitting diodes can be achieved if the side reflector is provided with steps such that the light rays produced by the light-emitting diodes emanate from the transparent cover at least approximately parallel to one another over an area based on the reflector size and the number of light-emitting diodes.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.